CS 7450 Information Visualization

1
Introduction

• CS 7450 - Information Visualization
• Aug. 24, 2000

2
Exercise

• Picnic directions

3
Data Explosion

• Society is more complex
• There simply is more stuff
• Computers, internet and web give people access to
  an incredible amount of data
• news, sports, financial, purchases, etc...

4
Data Overload

• Problem How to make use of the data
• How do we make sense of the data?
• How do we harness this data in decision-making
  processes?
• How do we avoid being overwhelmed?

5
The Challenge

• Transform the data into information
  (understanding, insight) thus making it useful to
  people

6
One Approach

• Provide tools that present data in a way to help
  people understand and gain insight from it
• Cliches
• Seeing is believing
• A picture is worth a thousand words

7
Exercise Redux

• What did you put on your paper?
• Text?
• Pictures?
• People work differently

8
Visualization

• Often thought of as process of making a graphic
  or an image
• Really is a cognitive process
• Form a mental image of something
• Internalize an understanding
• The purpose of visualization is insight, not
  pictures
• Insight discovery, decision making, explanation

9
Main Idea

• Visuals help us think
• Provide a frame of reference, a temporary storage
  area
• External cognition
• Role of external world in thinking and reason
• Examples?

10
Information Visualization

• What is information?
• Items, entities, things which do not have a
  direct physical correspondence
• Notion of abstractness of the entities is
  important too
• Examples baseball statistics, stock trends,
  connections between criminals, car attributes...

11
Information Visualization

• What is visualization?
• The use of computer-supported, interactive visual
  representations of data to amplify cognition.
• From Card, Mackinlay Shneiderman 98

12
What Its Not

• Scientific Visualization
• Primarily relates to and represents something
  physical or geometric
• Examples
• Air flow over a wing
• Stresses on a girder
• Weather over Pennsylvania

13
Information Visualization

• Components
• Taking items without a direct physical
  correspondence and mapping them to a 2-D or 3-D
  physical space.
• Giving information a visual representation that
  is useful for analysis and decision-making

14
Two Key Attributes

• Scale
• Challenge often arises when data sets become very
  large
• Interactivity
• Want to show multiple different perspectives on
  the data

15
Domains for Info Vis

• Text
• Statistics
• Financial/business data
• Internet information
• Software
• ...

16
Examples

• Images
• Minivan comparison, Atlanta air traffic,
  London/Paris subways
• Videos
• Film Finder (Maryland)
• Timelines (MIT)
• Software (saw last time)
• Map of the Market (SmartMoney)
• SunBurst (GT)

17
Tasks in Info Vis

• Search
• Finding a specific piece of information
• How many games did the Braves win in 1995?
• What novels did Ian Fleming author?
• Browsing
• Look over or inspect something in a more casual
  manner, seek interesting information
• Learn about crystallography
• What has Jane been up to lately?

18
Tasks in Info Vis

• Analysis
• Comparison-Difference
• Outliers, Extremes
• Patterns
• Assimilation
• Monitoring
• Awareness

19
Knowledge Crystallization

• Information foraging
• Search for schema (representation)
• Instantiate schema
• Problem solve to trade off features
• Search for a new schema that reduces problem to a
  simple trade-off
• Package the patterns found in some output product

From CMS 98
20
How Vis Amplifies Cognition

• Increasing memory and processing resources
  available
• Reducing search for information
• Enhancing the recognition of patterns
• Enabling perceptual inference operations
• Using perceptual attention mecahnisms for
  monitoring
• Encoding info in a manipulable medium

21
Process
task
Raw data
Data tables
Visual Structures
Views
Data transformations
Visual mappings
View transformations
22
Sources Used

• CMS book
• Spence book